//CAC1  EXEC PGM=A,ADDRSPC=VIRT

This EXEC statement executes program A and requests virtual (pageable) storage. Because the REGION parameter is not specified, the storage available to this job step is the installation default or the region size specified on the JOB statement.

//CAC2  EXEC PROC=B,ADDRSPC=REAL,REGION=80K

This EXEC statement calls procedure B and requests central (nonpageable) storage. The REGION parameter specifies 80K of storage.